Abstract

Subgrain size, Dislocation density '9\Vý85t\ACT (Continue on roverse if necessary and idenotiy by block number) 2'tiis thesis reports trends in the variation of the subgrain size and density of dislocations not associated with subgrain boundaries (forest dislocations) in high purity aluminum with strain during primary and steady-state creep at temperatures in the power-law regime utilizing torsional deformation. Any microstructural feature responsible for strength is expected to be constant during steady-state deformation. Earlier work addressed changes in the subgrain size over a wide range of steady-state